Considering fast prime lenses, there is the panasonic 42.5 and the olympus 45mm, and after them there is the olympus 75mm.
But between 45mm and 75mm there is a huge gap, so a 60mm 1.7 or 1.8 lens would be very welcome, very useful for portraits and face closups.
One of the lenses I use most often is the Sigma 60mm. Maybe I got lucky and got a super sharp one, but the IQ is amazing.
For faster lenses in the range, I use a speedbooster with some of the mid tele lenses, even the old Nikkor 85mm/2
I used to use the Rokkor 58 (basically 60...) but the Sigma 60mm is sharper.
For portraits, it really is hard to beat the Olly 45/1.8 or any of a number of MF primes in the 40-85 range, with or without speedbooster.
The Olly 45 is such a good portrait lens it's worth shooting a tiny bit closer.
Basically MFT has "85" and "150"
When usually it goes 85 then 135 for fast primes. So the gap is a little bigger, but not by much.
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